Applicants' employer, Surface Optics Corporation, developed during the 1990's a series of small rugged portable spectrometers. Some of these units have been successfully marketed as model SOC400. These units were powered by a 12 volt power supply, such as a car battery and required the addition of an associated computer, such as a desk-top or lap-top computer, to operate. The units included optical components for producing illumination at a variety of controlled spectra. These components include systems utilizing broad band light sources and optical filters to produce illumination at several specific wavelengths. Interferometers were used to produce illumination at a series of wavelengths. These devices are very useful for measuring diffuse reflectance of a target or sample. The spectra of the reflectance can identify target material. These units have been engineered into modular systems in which various “heads” could be interchanged allowing a single unit to be used for a variety of purposes. These heads included (1) an attenuated total reflectance (ATR) head, (2) a specular 50 degree reflectance head, (3) a grazing angle 75 degree specular reflectance head, (4) a gas cell head, (5) an integrating sphere head. With some of the devices only a single spectral point is measured and in other devices several spectra data is measured. Features of these prior art devices are described in the following patents, all of which are incorporated herein by reference:
U.S. Pat. Nos. 5,424,543, 5,821,535 and 5,949,074 describing imaging spectrometer units and U.S. Pat. Nos. 5,714,758 and 6,147,350 describing rugged portable units with Fourier transform infrared spectrometer illumination for diffuse reflectance spectral measurement.
The SOC400 has been a very successful product; however, the unit requires a separate power source and a computer as support equipment and in many applications a rolling cart to transport it. These components are depicted in FIG. 1 in the U.S. Pat. No. 5,714,758 patent. The measuring apparatus is depicted at 22 and the support equipment is depicted at 24. The support equipment includes a battery and a table-top computer 34 that controls the measuring apparatus, receives data there from, and stores the data, analyses the data, reports and/or displays the data.
What is needed in an even easier to use more compact modular portable spectrometer.